Had the same mag issue with my EAA 10 (mags had a red follower). Sent all 3 back to EAA and they replaced them with 3 Mec-gar mags at no charge. Haven't had a problem since. I have medium hands and the grip is good for me. For reference Glock 20 does not fit in my hand properly.... need the SF.
Good info. My mags were either a red or orange follower as well. When I had mine though, EAA's customer service was pretty bad, and it wasn't worth waiting 6 months or more for them to get around to replacing mags, it made more sense to move to a different gun.
I'll also say that I had the same full size Witness steel model in 45 Auto, and it was one of the best 45 Autos I've ever had, with never a mag issue. The problems I experienced were strictly with the 10mm magazines.
Your comment on the G20 is par for the course with gen 2 & 3 G20 and G21 frames; they don't fit most peoples hands. The gen 3 SF and all gen 4 guns are shorter front to back in the grip, and fit most people's hands much better. They're also a lot more common these days than the older big frames that nobody wants.
